Improvement in rock-drilling machines



E. S. WINCHESTER.

Roar: DRILLING MACHINE.

No. 181,386. Patented Aug.2z,1s7e.

WLM? 3%?,

UNITED STATES EDWARD S. VVINOHESTER, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN ROCK-DRILLING MACHINES.

Specification forming part of Letters Patent No. l 81,386, dated August22, 1876; application filed June 20, 1876.

To all whom tracy concern:

Be it known that I, EDWARDS. WINCHES- TER, of Boston, in the county ofSuffolk and 3 State of Massachusetts, have invented certain Improvementsin Rock-Drilling Machines, of which the following is a specicationzl Myinvention consists of certain improvel ments in vrock-drills, ashereinafter more fully f described, the object being,v to produce adrill j that shall be more compact and capable of being used in a morerestricted space than l those hitherto made, and which shall be madeWithout any outside steam-chamber, and with g its valve located withinor upon the piston, so E as to be operated by the momentum of the lpiston.

Figure l is a longitudinal section, showing the piston at one end of itsstroke; Fig. 2.is similar view, showing the piston at 'the oppo: ,Y siteend of its stroke, and Fig.3 is aviewof a piece detached.

In order to construct a drill on my plan, I provide a cylinder, A,having a chamber, G, extending about one-half its length, in which thepiston-head H is to play, the extended g portion being bored out ofsmaller diameter, as a guide for the piston, a part of its length, withan annular recess or chamber, D, for the escape-steam, and having at itsend beyond this a recess for the insertion and retention of i a bul'eror elastic ring for the piston to strike against as it plays back andforth. The piston- Q head H is fitted to play in the steam-chamber C,the steam pressing on its entire surface for the downstroke, `While onthe return-stroke the steam operates on the projecting portion only. Theinlet-port by which the steam eni ters the chamber C below the pistonconsists of a passage, a, which may be made at any l point in thecylinder A, so as to enter at the front or lower end of the chamber,While the g theannular chamber D, which surrounds the lower part or neckof the piston, as shown in the drawings.

The piston has a longitudinal cavity made centrally in its upperportion, 4in which is escape-port Z is a simple hole opening out from lplaced a sliding balanced valve, V, as shown. i

This valve consists simply of a metallic plug l or short rod of such adiameter as to slide 5 easily to and fro in the bore or cavity in whichl in the drawings.

a is heid in the @yundeasaid valve being' turned off or reduced indiameter at its center for about one-third of its length, more or less,

thus leaving an annular space at its center, into which the steam entersfrom chamber G through a hole, b, bored through the side of therebyrendering-it a balanced valve. From this cavity or valve-chamber withinthe piston one or lnore passages, c, extends out through the end of thepiston-head H, opening into the steam-chamber G above or behind thepis.V

ton; and from near the/,upper end of the shown in Fig.yl, this chamber Dhaving an outlet, l, as previously described, and as shown For thepurpose of assistingtostart the valve upward I make another passa-gem,which extends from the outside of the pistou-to theI lower or' front endof theivalve-chamber, as

.shoWn in Figs. l and 2, the outer -end of this opening being so locatedthat it Will be brought Within the steam-chamber only when the pis.-

l ton has reached the limit of its upstroke, or

nearly so, as shown in Fig. 2, and sothat it will permit the escape ofsteam therefrom into act as a buffer, when the valve strikes, to re,

lieve it of the shock, if required.

In the drawings I have shown the valve and its chamber as circular incross-section, that b eingthe simplest and easiest of construction; butit is obvious that they may be rectangular or of other form, if desired,and operate the same. Y 1 5 With theV cylinder, piston, and. valve con,structed as above described, thefoperation Will'be as follows: Supposingthe piston and valve to be down, as represented in Fig. 1,

the steam will enter through the inlet-passage a into the chamber Cunder the head H, which Parr-filtra*l OFFICE. f

will cause the piston to rise. When it reaches the end of its stroke,and is suddenly stopped, the momentum imparted to the valve V will causeit to slide to the upper end of its chamber, this movement beingassisted by the steam entering through the passage p, and pressingagainst the lower end of the valve. As the valve is thus moved it willclose the passage n, at the same time opening the passage c, andpermitting the steam to pass from the chamber G below the head H inthrough the hole b into` the annular space around the valve V, and fromthence through passage c into the chamber C above the piston, therebystarting the piston back on its downstroke. As soon as it has moved downa very short dis tance the steam is shut o' from the passage 19 behindthevalve, and as it reaches the limit of its stroke the valve is againshifted by its momentum, thus opening the passage fn, which permits thesteam above the piston to escape into chamber D, and thence out into theatmosphere through opening Ul, the mouth of passage p entering thechamber D just before the stroke is completed, thereby relieving thevalve from the steam-pressure at its lower end, and leavin gjt free tomove,as described.

In this manner the parts will continue to operate the valve, shiftingits posit-ion at the end of each stroke by its momentum, without anyother aid, except that of the steam entering behind it through passageprand which is designed more especially to overcome the weight of thevalve, when the drill is in a perpendicular position, or nearly so.

In an engine constructed to be used solely in a horizontal position thispassage p may be omitted; but I prefer to use it, inasmuch as it affordsalso a sure means of shifting the valve to start the engine, in case itshould be stopped at the end of its upstroke, it-only being necessary insuch case to let on the steam, which would instantly lift the valve,

thereby admitting the steam to the upper end` of the chamber G, whichwould at once force the piston down, after which the valve would beoperated by its momentum, as before described.

It will at once be seen that whenever the piston is stopped at any partot' its stroke, either on the up or down stroke, the valve will beinstantly shifted, which is a veryimportant feature in rock-drills, forthe reason that if the drill be fed forward faster than the tool cuts itis necessary that the valve should reverse before the piston hascompleted its full stroke, or it will stop.

It will be observed also that the ports are so arranged as to change thestroke on the upward movement of the piston just before piston'hastraveled the entire length of the cylinder-chamber, thus allowing thepiston to cushion on the steam in the end of the chamber above thepiston-head.` Another important result ot' this construction is that thevalve does not move to open the exhaust-port until the tool has struckthe rock, the blow being delivered with a full head of steam ou thepiston, thus greatly increasing its efficiency.

In this class of machines much diiiculty has been experienced inconnecting the drill or cutting tool to the piston in such a'mauner thatthey would stand the severe tests Without breaking, and also inarranging the buffers against ,which the piston strikes.

In my present invention I construct the piston with a solid extension,which terminates in an enlargement or solid head, I, which is madeintegral with the rest of the piston, instead ot' being screwed on orotherwise fastened thereto, there being a longitudinal hole bored in theprojecting end for the reception of the drill or tool T, as shown.

The buffer consists ot' two rubber disks or rings, ff, with anintervening steel ring, k, as shown in Figs. 1 and 2. As this ring hcannot be slipped over the head I of the pistonrod, itis made in halves,as shown in Fig. 3. To secure the buffer in place, I provide a tubularsleeve, E, which is bored out internally so as to receive the buffer, asshown in Figs. 1 and 2this sleeve E being screwed into the end of thecylinder, and thereby securing the buffer firmly in place between theshoulder formed on the interior ot' the sleeve and a cor respondingshoulder formed on the interior of the cylinder.

As shown in the drawings, the piston-rod is provided with an annularshoulder, which, as the piston is forced down, comes in contact with thebuer, While on the upstroke the head or collar I strikes against theopposite side of the buffer.

By this construction the rubber cushionsor rings f are supported by thesteel ring h, `the force of the blow on the rubber being transmitted tothe ring h, which, being solid and unyieldin g, distributes the forceover its whole face, and transmits it to the ring f onthe opposite side,thus utilizing the elasticity of both rubber rings at each stroke, thismethod of supporting the rubber rings also preventing them from beingcut or worn, as they would be, were not the metallic ring interposed.

By this construction it will also be seen that while the buffer isprotected from injury by being inclosed within the extension of thecylinder, itis at `the same time located outside of the steam-chamber,where none but the exhaust steam comes in contact with it, theexhaust-chamber being open to the atmosphere. It will also be seen thatlthe rubber is also where the oil used to lubricate the piston-head doesnot come in contact with it, and that it is thus, protected from theinjurious etiect of the live steam, the oil, andv the particles of stoneor similar material. It will also be seen that by this arrangement, theshoulders of the piston, instead of striking against any portion of themetal, strike on the rubber rings of thebuii'er on each side, therebypreventing the destructive action that occurs where the metallic partscome in direct contact.- i l l I have shown a packing-ring, d, insertedin a recess in the interior of the cylinder A, but

' any other style of packing may be used, if

preferred.

As nearly all the drill can be made by lathe- Work, it is cheap toconstruct; but far more important is its compaotness, by WhichI amenabled to produce an effective operating-machine, so small that it canbe readily handled by a single person and used in almost any crevice,cut, or vein which is large enough to admit a man or operator, theentire length of the machine being but about eighteen inches, thusespecially adapting it for use in mining operations, and in places wherethe drills ordinarily made cannot be used for want of room. v

Another advantage is, the absence of valvelevers, stems, rods, cams,&;c., by which the number of. Wearing parts and the liability ofbreakage, as Well as first cost, Vare materially reduced.

While I have described it as being operated 2. In combination With thecylinder A, pro-f.7

vided with suitable steampassages, the piston P, having the valve Vfitted in a cavity therein, substantially as described, whereby thevalve is operatedwholly or mainly by the momentum imparted to it by themovements of,

the piston, as set forth.

v. 3. In combination with a valve arranged lto be operated by themomentum imparted to it by the movement of the piston, the inlet or portp, to admit steam or air to assist in moving or sustaining the valve, asset forth.

4. The buffer, composed of the rubber or elastic-rings ff, With theinterposed metallic ring h, in combination With the piston havingshoulders thereon, arranged to strike against the rubber on oppositesides, as set forth.

5. A rock-drill having a buer located Within an extension of thecylinder and outside of A the s team-chamber, substantially asdescribed.

EDWARD s. WINoHEsTER.

Witnesses:

G. O. L. DILLAWAY, M. S. WINoHEsTER.

